WebsocketServer.java Source code

Introduction

Here is the source code for WebsocketServer.java

Source

import java.io.IOException;
import java.util.concurrent.ExecutionException;
import javax.faces.bean.ApplicationScoped;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
import twitter4j.JSONException;
import twitter4j.JSONObject;
import twitter4j.TwitterException;

/*
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/**
 *
 * @author miguel
 */
@ApplicationScoped
@ServerEndpoint("/")
public class WebsocketServer {
    private static Session session;
    private static Streaming streaming;

    public WebsocketServer() throws TwitterException, IOException {
        WebsocketServer.streaming = new Streaming();
        // Reset application's preferences to ask the user to get a new token's PIN
        // (used for debugging).
        //streaming.resetPreferences();
    }

    public static void sendMessage(String message) throws IOException {
        session.getBasicRemote().sendText(message);
    }

    /**
     * @param session
     * @throws java.io.IOException
     * @throws twitter4j.TwitterException
     * @throws java.lang.InterruptedException
     * @throws java.util.concurrent.ExecutionException
     * @OnOpen allows us to intercept the creation of a new session.
     * The session class allows us to send data to the user.
     * In the method onOpen, we'll let the user know that the handshake was 
     * successful.
     */
    @OnOpen
    public void onOpen(Session session)
            throws IOException, TwitterException, InterruptedException, ExecutionException {
        WebsocketServer.session = session;
        System.out.println(session.getId() + " has opened a connection");
    }

    /**
     * When a user sends a message to the server, this method will intercept the message
     * and allow us to react to it. For now the message is read as a String.
     * @param message
     * @param session
     * @throws twitter4j.TwitterException
     * @throws java.io.IOException
     * @throws java.lang.InterruptedException
     * @throws java.util.concurrent.ExecutionException
     */
    @OnMessage
    public void onMessage(String message, Session session)
            throws TwitterException, IOException, InterruptedException, ExecutionException, JSONException {
        if (WebsocketServer.session == session) {
            System.out.println("Message from " + session.getId() + ": " + message);

            JSONObject data = new JSONObject(message);
            String messageType = data.getString("message");

            switch (messageType) {
            case "startStreaming":
                // Initialize application's access token.
                streaming.initializeToken();
                break;
            case "accessTokenPin":
                streaming.createApplicationAccessToken(data.getString("pin"));
                break;
            case "stopStreaming":
                streaming.stopStreaming();
                break;
            }
        }
    }

    /**
     * The user closes the connection.
     * 
     * Note: you can't send messages to the client from this method
     * @param session
     */
    @OnClose
    public void onClose(Session session) {
        if (WebsocketServer.session == session) {
            System.out.println("Session " + session.getId() + " has ended");
        }
    }

    @OnError
    public void onError(Throwable t) {
    }
}